Shuguang tubes, any experience with their EF86?

[My3gger]

Hi,

i need to change EF86 and E88CC tubes in Redd47 type mic preamplifier. Guy who was providing me with nice NOS tested Tesla or RFT tubes doesn't have them anymore, he became reseller of JJs. Local company sold me two EF86s by EH for RCA BA-2 type amp, i asked for one with low noise and the other with a little more relaxed specifications regarding this because it went into output stage. Both are wired as triodes, so can't say if pretty low noise of both means anything when wired as pentode.

A few weeks ago friend and i went to local repairmen to do some work on Fender Pro Reverb (70W ultra-linear), where he replaced many lytics and all tubes. They were bought from TAD, he told us two output 6L6s are made by Shuguang with 6 months warranty. After a few hours of playing gently one 6L6 developed what seemed slight microphonics. A friend made trip back to repairmen who added retairners for both 6L6s, but "microphonics" were still present at slightly lower level i was told. From day one preamp made sounds of tearing paper after turning it on and before turning off standby switch. This happened in standby about two times for a few seconds. When working, so not in standby for like 20 minutes anymore, there was only this slight "microphonics". After 5 days a friend was playing it and heard slight band, after that amp stopped working. Tube with 6 months warranty failed, this was also confirmed by repairman.

Before this event i wanted to order Shuguang EF86 from TAD, it is this tube:
http://www.tubeampdoctor.com/en/shop_TAD_Premium_Tubes_TAD_Pre_Amp_Tubes_SELECTED/EF86_6267_TAD_Premium_Selected_549
For E88CC NOS Ei Niš:
http://www.tubeampdoctor.com/en/shop_TAD_Premium_Tubes_TAD_Pre_Amp_Tubes_SELECTED/E88CC_NOS_TAD_Premium_Selected_balanced_4681
Both have 6 months warranty, but after this problem with 6L6 i'm really not sure about buying anything from them, especially not EF86 comming from the same factory under same conditions as failed 6L6. Preamp is used in the studio all the time, before it had Winded C EF86 and Tesla E88CC, where EF86 became noisy and E88CC also needs replacement. The problem was heat because it was way too closed in rack, i couldn't convince them to get perforated cover, etc. I knew closed box isn't good for E88CC biased like this and closed inside rack and enclosure without any means of ventilation. From start we only want to check how good preamp sounds compared to others and guy of course liked it so much that he didn't want anyone else to touch it, or me finishing work.

Well, long post about two things, my question is about your experiences with Shuguand EF86s and TAD. Would you buy from them EF86 for 20eur when i can get a few Winged C for the same money? One will be good for sure, maybe all of them. And what about EH EF86, they seem to make good tubes, i used other types without problems, of course some had a bit of noise as V1 if not selected by seller, never had fails for years. E88CC shouldn't be a problem it seems, although i mostly used NOS Teslas until they became expensive and what remains is a lot of so so tubes. Thanks.

 

[ruffrecords]

I use 6922EH in all my designs. Never had a problem with them. The Chinese got into tube manufacturing late and they are not very good at it. The Russians have been doing it for many decades. Personally I would choose current Russian manufacture every time.

Cheers

Ian

 

[pucho812]

We use 6922 by EH in our stuff, we still have issues but when your talking around 1% do not meet our standard, it's not that much of a problem, and EH is always will to repalce new ones if we find them to be an issue.

 

[mjrippe]

I use 6922EH in all my designs. Never had a problem with them. The Chinese got into tube manufacturing late and they are not very good at it. The Russians have been doing it for many decades. Personally I would choose current Russian manufacture every time.

Cheers

Ian

Agreed.  Chinese tubes *in general* are inferior.  I know TAD hand picks their tubes, but bad ones still get through and you are paying a premium for their selection.  JJ and EH are both relatively good, though not like the old days.

 

[ruffrecords]

Agreed.  Chinese tubes *in general* are inferior.  I know TAD hand picks their tubes, but bad ones still get through and you are paying a premium for their selection.  JJ and EH are both relatively good, though not like the old days.

I have had no trouble with EH but JJ E88CC tubes I find to be very inconsistent. I just don't use them any more.

Cheers

Ian

 

[gyraf]

We use 6922 by EH in our stuff, we still have issues but when your talking around 1% do not meet our standard, it's not that much of a problem, and EH is always will to repalce new ones if we find them to be an issue.

You buy direct in bulk, and get not-already-deselected-by-others tubes? How can I get a deal like this?

Jakob E.

 

[Goodizzy]

Maybe I misread the post Ian, but to clarify, you use EH for both the EF86 and E88CC valves in the REDD.47? 

 

[Rob Flinn]

I used some Shugang KT100 in a pair of Leak TL50 that I had a few years ago.  They were supposed to be a ruggedised version of a KT88.  What happened with one of them was that after it had warmed up for about 20 mins it's characteristics completely changed, so all the test voltages that had been fine initially were all over the place.  Basically they're not very good valves.

 

[Goodizzy]

That's interesting Rob as I had a similar happening with a Leak TL25+ and Shuguang KT66 valves.  I had bought a matched quad and one of the two valves I placed in circuit flashed blue and blew the fuse after a similar amount of time.  Checked bias thinking maybe an older component had caused the problem, but it was perfectly fine. 

The other three valves appear/ sound okay to my ears, though with the staggering price of NOS KT66, I admittedly have nothing to compare them to.

 

[ruffrecords]

Maybe I misread the post Ian, but to clarify, you use EH for both the EF86 and E88CC valves in the REDD.47?

Yes and no. I use EH EF86 and 6922 but not in a RED47.

Cheers

Ian

 

[mjrippe]

I have had no trouble with EH but JJ E88CC tubes I find to be very inconsistent. I just don't use them any more.

Cheers

Ian

Ahhh, that is interesting.  I was speaking in more general terms.  I have not actually used the E88CC  from either company, but I do now recall some EH 12BH7 tube failures that seemed premature.  And I think that current production 6386 are crap for the cost, but now I'm just sounding old and angry 

 

[ruffrecords]

Ahhh, that is interesting.  I was speaking in more general terms.  I have not actually used the E88CC  from either company, but I do now recall some EH 12BH7 tube failures that seemed premature.  And I think that current production 6386 are crap for the cost, but now I'm just sounding old and angry 

I have used a small number of EH 12BH7 but not enough to form an opinion. They have given no trouble so far. So far I have found most NOS tubes to be rubbish (especially for noise) and overpriced. Current production tubes are better and much more consistent.

Cheers

ian

 

[My3gger]

Yes and no. I use EH EF86 and 6922 but not in a RED47.

Are those EH EF86 wired as pentodes? I know you were testing EH 6CG7, your papers make me think there is no reason using them instead of triode wired EH EF86. If so, can you give comments about typical bias drift (does it changes in first half hour, during a few days, etc), other parameters compared to good NOS, durability, noise, whatever. E88CC and 6CG7 are used often too, do you find them as good too? If others know this things it would be nice to share our experiences.

I have used a small number of EH 12BH7 but not enough to form an opinion. They have given no trouble so far. So far I have found most NOS tubes to be rubbish (especially for noise) and overpriced. Current production tubes are better and much more consistent.

Cheers

ian

I bought quite a few NOS EF86/EF806, 6N32P, 6CG7, 6SN7, E88CC, 6N23P, 6N1P, 6N6P and similar. Using them as examples of good NOS tubes when doing comparisons with new production. This was during 2-3 years from about 2005 when they were still pretty cheap and many came well tested with results, except one they work very well and don't show any signs of use even after extensive comparisons and sometimes real use.
Searching eBay it seems many "NOS" are actually used or faked, although i can still find good prices for nice tubes which look like genuine NOS with return policy. I'm talking sellers with at least 1000 tubes sold and 100% positive feedback. EF86 like this are mostly Winged C from 80's, Tesla, RFT, or Tungsram. Western have at least double price, often with test results and some don't look new. But tubes like E88CC are way overpriced imo too, getting like 6 NOS 6N23P for 24eur is a bit suspicious to me, they might work, but i doubt anywhere nearly as good as Western or good Eastern we could get years ago. I'm guessing it would be worth trying to get a seller who has NOS of tubes we use a lot, which seems quite hard judging by search in the last few weeks.
Do others feel the same as Ian, are this NOS bad and it makes a lot more sense getting new?

p.s.: Another thread mentions problems with inconsistent JJ power tubes. This are my experiences too, although i don't have enough of them to say it for sure myself. Quite a few others told me the same thing, mostly regarding power amp outputs. We had some problems with their ECC88 which were run properly, not like E88CC. One of problems was burned anode, never seen that with properly biased and designed small signal circuit. Redd47 has E88CC biased quite hot, but we know that and there are historic notices about it too.

 

[ruffrecords]

Are those EH EF86 wired as pentodes?

Yes, they are

I know you were testing EH 6CG7, your papers make me think there is no reason using them instead of triode wired EH EF86.

The main reason is a 6CG7 has two triode in one envelope.

If so, can you give comments about typical bias drift (does it changes in first half hour, during a few days, etc), other parameters compared to good NOS, durability, noise, whatever.

Never has any problems with bias drift. The main advantage of current production is superior and more consistent noise performance. I have found large percentages of NOS tubes to be noisy and very many are extremely microphonic. It may be an ageing issue. The biggest issues I have had with tubes for mic pres is noise and microphonics. Even different brands of 12AX7 for example have completely different microphonic characteristics.

E88CC and 6CG7 are used often too, do you find them as good too? If others know this things it would be nice to share our experiences.

I must have bought around 100 NOS 6CG7. You will have seen from my papers that the characteristics vary between brands. The most consistent ones were Matsushita but they had relatively short plates which leads to higher distortion. The parameter that varies most in NOS types is  again noise and microphonics.

I use 6922EH because they are the most consistent. JJ E88CC are definitely inferior. I had not yet found a good NOS E88CC.

I bought quite a few NOS EF86/EF806, 6N32P, 6CG7, 6SN7, E88CC, 6N23P, 6N1P, 6N6P and similar. Using them as examples of good NOS tubes when doing comparisons with new production. This was during 2-3 years from about 2005 when they were still pretty cheap and many came well tested with results, except one they work very well and don't show any signs of use even after extensive comparisons and sometimes real use.

I have bought lots of NOS 6N23P because they are quite close to a 6922. But again, they are vary variable.
Cheers

Ian

 

[My3gger]

I use 6922EH because they are the most consistent. JJ E88CC are definitely inferior. I had not yet found a good NOS E88CC.
I have bought lots of NOS 6N23P because they are quite close to a 6922. But again, they are vary variable.
Cheers

Ian

NOS silver pin Tesla E88CC never gave me a problem when used in V2 position. Measuring them show they can be used as inputs too where low noise is more important, microphonics aren't issue even after years of use. Two same tubes with gold pin and grid bought from the same seller didn't perform as well as silver pin. Probably because price was pretty high at that time (they are cheaper now than 6-7 years ago) and seller sent bad ones. One had loose part inside, the other is microphonic, both still work for the tests.
Can't say if EH are more durable, NOS Tesla without signs of use make up to 10.000 hours ime. After thousand hours or so letters, O getter and part of glass below flash getter can become slightly brown. It depends of biasing and heat dissipation, so this is not the same with all Tesla E88CC. Sometimes pins show signs of use when looking at eBay, my tubes still have nice shiny silver pins even after hard work. I know construction of this tubes pretty well, eBay still has a lot of them at pretty low prices, so i would try them if using as many as you do.
More research at eBay and replies here convinced me i better buy new, even if i had good experiences in the past. Maybe other tubes that i only use for comparisons seem good because of low hours, luck, mostly the same source, etc. And at least NOS Tesla EF806 and E88CC sound the same to me as EH.

 

[ruffrecords]

Thanks for the tip about NOS Tesla E88CC. I will look out for them. I think i may have bought a couple from Langrex.

I never understood how NOS tubes suddenly became available with gold pins. I have been using tubes since the early 60s and I do not ever recall seeing ones with gold pins. I suspect this is a modern audiiophool thing. To me, any NOS tube with gold pins is suspicious.

Cheers

IAn

 

[Conviction]

Thanks for the tip about NOS Tesla E88CC. I will look out for them. I think i may have bought a couple from Langrex.

I never understood how NOS tubes suddenly became available with gold pins. I have been using tubes since the early 60s and I do not ever recall seeing ones with gold pins. I suspect this is a modern audiiophool thing. To me, any NOS tube with gold pins is suspicious.

Cheers

IAn

European SQ-labeled tubes more often than not came with gold pins. That was standard. Check out the Philips E80CC for example. Or open up a random Oltronix oscilloscope from the 60's.

 

[ruffrecords]

European SQ-labeled tubes more often than not came with gold pins. That was standard. Check out the Philips E80CC for example. Or open up a random Oltronix oscilloscope from the 60's.

OK, thanks for that. I did not know that.

Cheers

Ian

 

[PRR]

> how NOS tubes suddenly became available with gold pins

For some time in the 1970s-1980s+, US Radio Shack Realistic-branded tubes had "gold" pins.

As they were LifeTime Guarantee, this ensured that non-RS duds were not taken-back under guarantee.

I never thought the RS R-LT tubes were more than medium/high grade standard production, with custom ink and a light "gold" flash. In later years, many were from Japan, but true Telefunkens have been seen. I have heard of getting true SQ tubes through this channel but that seems to be rare.

The art of gold plating has been around hundreds of years or longer. I can buy a battery holder and "pen" to put real Gold on small objects. The "gold tone" solutions must be stock products in many electronics factories.

 

[CJ]

Amperex 6267

mount it with rubber grommets, reduce screen voltage,

like trying to get a fine tuned sports car to run right without blowing up (microphonics)

but when you do find a good one there is no other sound like it,

this guy is 12 bucks on evilbay,  no orange script, but hey, jus sayin,  wtf, over?